The rebel Free Syrian Army has given the government of President Assad 48 hours to abide by the terms of the UN ceasefire or it says it will consider that it is no longer bound by it.
The BBC's Paul Wood, who has been travelling undercover inside Syria for the past three weeks, told the Today programme that the ceasefire exists "in name only" and most people in Syria do not believe the UN plan will work.
"There is no ceasefire and the threat to lift it will just mean business as usual," he said.
Speaking to Sarah Montague, he explained that people in Syria always argued that a sectarian war was not in their tradition but that opinion is now "beginning to change".
One activist - who previously denied that a civil war was coming - told him that the Syrians will look back at May and say "this was the month that the civil war began in earnest".
The country is a "hair's breadth" from all-out sectarian civil war, he said.
People feel "utterly abandoned" he says, as they hear the declarations by Western governments condemning the Syrian regime and "expect something to follow".
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